Gang Yang

Bio: Gang Yang is an academic researcher from University of British Columbia. The author has contributed to research in topics: Dissipation & Fish migration. The author has an hindex of 3, co-authored 6 publications receiving 246 citations.

Wave Interactions with Vertical Slotted Barrier

Abstract: The present paper outlines the numerical calculation of wave interactions with a thin vertical slotted barrier extending from the water surface to some distance above the seabed, and describes laboratory tests undertaken to assess the numerical model. The numerical model is based on an eigenfunction expansion method and utilizes a boundary condition at the barrier surface that accounts for energy dissipation within the barrier. Numerical results compare well with previous predictions for the limiting cases of an impermeable barrier and a permeable barrier extending down to the seabed. Comparisons with experimental measurements of the transmission, reflection, and energy dissipation coefficients for a partially submerged slotted barrier show good agreement provided certain empirical coefficients of the model are suitably chosen, and indicate that the numerical method is able to account adequately for the energy dissipation by the barrier. The effects of porosity, relative wave length, wave steepness, and irregular waves are discussed and the choice of suitable parameters needed to model the permeability of the breakwater is described.

Wave interactions with double slotted barriers

Abstract: The present article outlines the numerical calculation of wave interactions with a pair of thin vertical slotted barriers extending from the water surface to some distance above the seabed, and describes laboratory tests undertaken to assess the numerical model. The numerical model is based on an eigenfunction expansion method and utilizes a boundary condition at the surface of each barrier which accounts for energy dissipation within the barrier. Comparisons with experimental measurements of the transmission, reflection, and energy dissipation coefficients for partially submerged slotted barriers show excellent agreement and indicate that the numerical method is able to adequately account for the energy dissipation by the barriers.

Numerical Study of Landslide-Generated Waves

Abstract: A time-domain boundary element method is developed to simulate linear waves generated by a wave paddle or a horizontal-moving landslide of an arbitrary profile. In this approach, a time-integration procedure is used to apply the boundary conditions, and the wave field at each time step is solved by an integral equation method based on Green’s theorem. Numerical models in three dimensions are developed to simulate waves generated by landslides. The models were validated against theoretical and experimental results on comparative wavemaker problems. Numerical simulation results on landslide-generated waves demonstrate a number of features of interest. Design curves for engineering applications are also developed for quick estimate of magnitudes of landslide-generated waves in engineering applications.Copyright © 2004 by ASME

Frequency Domain Dynamic Analysis of a Floating Bridge

Abstract: This paper describes the methodology used in the dynamic analysis of a floating bridge across Okanagan Lake in Kelowna, British Columbia. The design wind conditions were obtained through the analysis of wind data collected at two local airports and the bridge site. The design wave conditions were calculated using numerical wave hindcasting techniques and a short-crested sea state was modeled using a directional wave spectrum. Hydrodynamic coefficients were calculated using a two-dimensional wave diffraction model. The dynamic analysis was conducted using a frequency domain approach which provides population statistics for responses. The sensitivity of the results to changes in various parameters was evaluated, notably the influence of the node spacing along the spine beam in the structural model, and the influence of frequency dependent hydrodynamic coefficients.

Design of Moorings For Complex Fish Passage Project

Abstract: Westmar Consultants designed a mooring system for a large floating fish passage facility subject to 18.5 m water level fluctuations in the forebay of a deep-water reservoir in northwest Washington State, using OrcaFlex software developed for offshore oil rigs. The design included extensive numerical modeling to accommodate the large water level fluctuations and high wind and current loads on the floating structures and nets. This system replaced the original, which was installed during dam construction in 1959. The paper will describe this environmental project that uses state-of-the-art mooring design technology to enable salmon migration past dams and other river obstructions that do not otherwise allow for fish passage.

Hydraulic performance and wave loadings of perforated/slotted coastal structures: A review

Abstract: This paper reviews recent progress in the study of perforated/slotted breakwaters, with an emphasis on two main groups of such breakwaters: (1) perforated/slotted breakwaters with impermeable back walls, and (2) perforated/slotted breakwaters without a back-wall. The methods commonly used to simulate the interactions between such structures and various linear/nonlinear waves are summarized. The transmission and reflection characteristics of perforated/slotted breakwaters in these two groups are reviewed extensively. Several methods for calculating wave forces on perforated caissons are also reviewed. Some recent works published in Chinese journals, which are generally not well-known to non-Chinese researchers, are reviewed with a hope that these works can be beneficial to other researchers working in this area.

Hydrodynamic modeling of perforated structures

Abstract: A hydrodynamic model of perforated or slotted structures is proposed. It is asymptotic in the sense that the openings are supposed to be infinitely small and numerous, and the wall thickness to be nil. At variance with other work, a quadratic, not linear, law, relating the pressure differential to the traversing velocity, is assumed. As a result the hydrodynamic coefficients (added mass and damping) become amplitude dependent. The model is applied to bodies of various shapes including cylinders, plates and disks, in forced motion or submitted to incoming waves. Good agreement with experimental data is generally observed.

Porous effect parameter of thin permeable plates

Abstract: The present paper aims at getting the porous effect parameter G of a thin permeable wall. The reflection and transmission coefficients of a thin vertical porous wall with different porous shapes an...

Hydrodynamic performance of pile-supported OWC-type structures as breakwaters : an experimental study

Abstract: Oscillating water column (OWC) is one of the mechanisms for extracting wave energy from ocean waves. In this study, we experimentally investigated the hydrodynamic performance of a pile-supported OWC structure as a breakwater, for which the air-flow through a small opening in the top cover contributes to energy extraction from waves and reduction in transmission coefficients. The effects of relative breadth, draught and opening conditions on wave reflection, wave transmission, energy dissipation and the pressure fluctuation inside the OWC chamber were examined. Compared with other types of pile-supported breakwaters, the hydrodynamic performance of the pile-supported OWC structure is remarkable and the pile-supported OWC structure has the potential for wave energy utilization.

Wave interactions with double slotted barriers

Abstract: The present article outlines the numerical calculation of wave interactions with a pair of thin vertical slotted barriers extending from the water surface to some distance above the seabed, and describes laboratory tests undertaken to assess the numerical model. The numerical model is based on an eigenfunction expansion method and utilizes a boundary condition at the surface of each barrier which accounts for energy dissipation within the barrier. Comparisons with experimental measurements of the transmission, reflection, and energy dissipation coefficients for partially submerged slotted barriers show excellent agreement and indicate that the numerical method is able to adequately account for the energy dissipation by the barriers.